POJ 1988 Cube Stacking

题目地址

total[x]记录最下方木块是x，这一堆总共有多少木块

under[x]记录x木块下面有几块木块

#include<iostream>#include<cstdio>#include<queue>#include<vector>#include<cctype>#include<cstring>#include<algorithm>using namespace std;const int maxn=30000 + 5;int Par[maxn],total[maxn],under[maxn];int getPar(int x){if(Par[x]==x) return x;int p=getPar(Par[x]);under[x]+=under[Par[x]];  //加上到那一堆之前的所有根节点 Par[x]=p;return p; }void merge(int a,int b){int p1=getPar(a);int p2=getPar(b);if(p1==p2) return ;Par[p2]=p1;under[p2]=total[p1];total[p1]+=total[p2];}int main(){int N;cin>>N;for(int i=1;i<maxn;i++){total[i]=1;under[i]=0;Par[i]=i;}string cmd;while(N--){cin>>cmd;if(cmd[0]=='M') {int x,y; cin>>x>>y;merge(y,x);}else {int x; cin>>x;getPar(x);cout<<under[x]<<endl;}}return 0;}